1. Field of the Invention
The present invention relates to a motor driving device, an integrated circuit device, a motor apparatus and a motor driving system, and more particularly, to a motor driving device an integrated circuit device, a motor apparatus and a motor driving system which drive a motor based on operation command information transmitted from a higher-level device.
2. Description of the Related Art
Regarding a method of transmitting operation command information about an operation of a motor from a higher-level device such as microcomputer to a motor driving device, there have been known a method employing a parallel data format using a parallel bus and a method employing a serial data format using a serial bus.
For example, JP-B-4,023,299 discloses a method of transmitting data in a parallel data format via a parallel bus between a higher-level device and a motor driving device.
Also, JP-A-2000-324896 discloses a method of transmitting data in a serial data format via a serial bus between a higher-level device and a motor driving device.
JP-A-2008-263678 discloses a servo motor control device which performs serial communication between a CPU substrate and a servo substrate and bi-directionally converts serial data into parallel data in the servo substrate.
Those data transmission methods respectively have advantages and disadvantages. Any one of those methods is adopted in a motor driving system which transmits operation command information from a higher-level device to a motor apparatus to drive a motor. According to the parallel data format method disclosed in JP-B-4,023,299, when the number of motor to be controlled, i.e., the number of the motor driving devices is two or more, a problem may occur. That is, the number of wirings for transmitting the operation command information to the respective motor control devices is obtained by multiplying the number of the operation command information by the number of the motor control devices. Therefore, the number of wirings is increased in a device having a plurality of motors mounted therein. As a result, it is necessary to provide a space for mounting the wirings, and thus it is difficult to make the device having the motors mounted therein smaller and to reduce the space. Also, the faulty wiring may be caused due to the increase in the number of the wirings.
The serial data format method disclosed in JP-A-2000-324896 may solve the problem occurring in the method disclosed in JP-B-4,023,299. However, in general, the serial data format transmission requires longer transmission time than the parallel data format transmission. Thus, when all control on the higher-level device and the motor driving device is performed through the serial data format, the overall performance of the system may be lowered.
As described above, the data transmission method between the higher-level device and the motor driving device includes the serial data format method and the parallel data format method. Regarding this, a motor driving device having different specification is required depending on which method is used to transmit the data.
That is, in a case where a motor is mounted in some apparatus, when a higher-level device of the apparatus outputs the operation command information of the motor by the parallel data format, it is necessary to use a motor driving device complying with the parallel data format transmission method. On the other hand, when the higher-level device outputs the operation command information of the motor by the serial data format, it is necessary to use a motor driving device complying with the serial data format transmission method. Therefore, regarding the motor driving device, it is necessary to provide a plurality of types complying with the parallel data format transmission method and the serial data format transmission method. As a result, the manufacturing cost of the motor driving device is increased due to the increase of the type of the motor driving device.
The above problem is particularly remarkable in a motor apparatus having integrated a motor and a motor driving device for driving the motor. That is, in this case, it is necessary to differently handle a motor apparatus complying with the parallel data format transmission method and a motor apparatus complying with the serial data format transmission method and it is not possible to use each motor apparatus in the other apparatus having the different transmission method and to commonly use the same.